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Regarding BGA Pad Lifting

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RV

#75346

Regarding BGA Pad Lifting | 9 February, 2016

I have pad lift issue during the rework on Motorola box DSR600 which has the fault of No log and No boot. Pad lifting pattern is on four corners.

I have checked the temeprature difference between the corners which is sam as center.

I have attached the profile picture and pad lifted pictures. If any body has any idea or sugestion, please let me know.

Attachments:

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#75347

Regarding BGA Pad Lifting | 10 February, 2016

I did a Google search => bga hosed by physics ... to find some older threads on the topic

BGA Bowing on the corners. - SMTnet [http://www.smtnet.com/Forums/index.cfm?fuseaction=view_thread&Thread_ID=6405 ] www.smtnet.com › Electronics Forum • Aug 22, 2003 - 5 posts - ‎1 author

BGA Bowing on the corners. printed circuit board assembly, surface mount ... For further discussion on the "being hosed by the physics": . BGA corners curling up during rework install... [http://www.smtnet.com/Forums/index.cfm?fuseaction=view_thread&Thread_ID=10987 ] 4 posts Oct 27, 2006

BGA rework: Coplanarity of Xilinx before and after reflow. [http://www.smtnet.com/Forums/index.cfm?fuseaction=view_thread&Thread_ID=8684 ] 3 posts May 16, 2005

BGA bake out.... [http://www.smtnet.com/Forums/index.cfm?fuseaction=view_thread&Thread_ID=7354 ] 3 posts Jun 28, 2004

More results from http://www.smtnet.com [https://www.google.com/search?q=bga+hosed+by+physics+site:www.smtnet.com&rlz=1C1LENP_enUS524US524&espv=2&biw=1680&bih=925&sa=X&ved=0ahUKEwjCx-_fpu3KAhWE7SYKHSgNCqcQrQIIJigDMAA]

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RV

#75349

Regarding BGA Pad Lifting | 10 February, 2016

Thanks Mr. Davef,

I had tried all possible factors to see good results. BUt I coudln't.

1. Baked Board 2. Board size is small. I used supporting pins so there is less chanches of bowing. 3. I tried to change the profile many times but result is nill. 4. I also talked with Arris People but I don't get any rigid solution. they were also strugling last six month or more. 5. I used three different machine with differet profile but output is same.

I am really not sure that issue is related to material, profile or pad and traces!!!

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#75350

Regarding BGA Pad Lifting | 10 February, 2016

Akrometrix is a company here in Atlanta that measures surface topography at reflow temperatures for the PCB and component. They have software that overlays the two sets of data to look for warpage problems. They offers this as a service as well as selling the equipment. It may be your PCB design. www.akrometrix.com

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#77112

Regarding BGA Pad Lifting | 16 February, 2017

Hello everyone.Ihave an Intel 855pm Northbridge and when i removed the chip,i lifted 4 pads one of them is VSS so i dont care it but the 3 other is:HI 4 ,HI8 and HI 6 (hub interface for cmos i/o or simply hub interface ).Are the vital or only testing points?I'll be very thankful for any help.

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#77123

Regarding BGA Pad Lifting | 19 February, 2017

Did you use Removal Profile for Rework or Reflow Profile to remove the BGA?

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#77125

Regarding BGA Pad Lifting | 20 February, 2017

In your pictures, many of the pads that have lifted from the PCB look as though they have no conenctions anyway. We often find that pads that aren't connected lift very easily.

One possible solution would be to bake the BGA's for 12 hours prior to fitting. We have had some issues with moisture causing bowing in some BGA's, and baking them solved most of the problems.

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#77155

Regarding BGA Pad Lifting | 1 March, 2017

Hi! I am Bob and pls forgive me if technical words I use are wrong. What may cause the BGA solder pad lift before or after reball? I am having problems where solder pad lifted during removal of bad solder ball. It also occurred during reball, where the pad lifted after BGA been melted 2-3 times due to misalignment of new solder balls. I must also say here that Solder between the pad and the BGA on the pads being lifted has not melted. So, when you lift the BGA, you also lift those pads with the unmelted solder with the BGA. These pads are probably sinking the heat to a large copper plane in a inner layer of the board. For this, you may want to add more heat to the board prior to lifting the component. Do this through: 1. Longer preheat 2. Increased bottom side heating 3. Longer soak

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